Sonic Potential Highway Turbulence

[Fit4Sonic]

I'm not a Sonic owner, yet. But I ran into this article on the web [from an owner] about Turbulence at Highway Speeds. I thought some of you may want to read it, and possibly submit any personal experiences with, and/or thoughts on this topic.


Article:

Chevy Sonic Hatchback Aerodynamic Turbulence At Highway Speeds
POSTED ON SUNDAY, NOVEMBER 13, 2011

"Recently I took the 2012 Chevy Sonic on a 200 mile road trip to really get a feel for the car. Overall the ride had little problems and the engine achieved more than 40MPG on the highway. Handling was responsive at highway speeds and ride comfort was also not too bad considering the class of car. Also, the numerous cup-holders really came in handy for the little road trip!

One noticeable concern would occur when the Sonic would get behind a semi-trailer at highway speeds. The turbulent airflow off the back of semi had a prevalent presence on the Sonic's aerodynamics. The little Sonic would shake and bounce around when inside the chaotic airflow coming off semi's similar to a van or large SUV. As this is my first experience with a vehicle from this class I found this somewhat surprising and not at all expected. I understand most every vehicle will feel this turbulent airflow but I would not have expected to notice so much. The problem would indeed be instantly remedied once the car was positioned outside of the turbulent airflow. The Sonic performed better in an open line with no vehicles in front for some distance.

I am not an engineer or scientist and these are just my personal observations but I wonder if a suspension modification or more effective rear spoiler would reduce these effects? So for any of those aftermarket shops who may come across this blog, I would love to see some suspension stabilization products developed for the Chevy Sonic hatchback."

-end of article

Post thoughts/feedback?

 

[AxelRipper]

Well the short wheelbase and stubbiness of it will cause an issue. That is why sedans will get better economy than hatches (especially on shorter cars).

I still haven't gotten mine yet, but I'll definitely notice if this is a case when I get it. I understand what it is talking about. My mother's old car (2006 Taurus) was HORRID at doing this. On the highway behind a semi, you were fighting it the whole time. I'll try to remember to post back review about what I see with my own hatch next week when I get it.

 

[theenico]

Hmmm. I just went on an 800mi round trip over Thanksgiving and didn't notice this phenomenon. Some of it could be driving style. I generally travel at a minimum of 5 over the posted and therefore rarely spend much time behind semis.

 

[laborsmith]

I took delivery of my 1.4 HB the day before Thanksgiving Day. On Thanksgiving Day a drove from Center Line to Clarkston with a detour around Lake Orion to go past my old home there then back to Center Line. That Friday I changed wheels and tires and am now running on Drag D-33 17 by 7.5 wearing Kuhmo Ecsta 225 by 45 tires. That Saturday a drove to Grand Rapids returning that evening. I state all this to show I drove the Sonic not only in a variety of conditions but with a variety of wheel/tire choices.

During these trips as well as several much shorter trips I was impressed by the stability of the ride. Needing to vary my speed on the freeways I spent much more time following semi trucks then usual during my Saturday sojourn. I did not experience unusual turbulence either following or passing these trucks.

In the past I have experienced the effects described, but in small sport cars such as Saab Sonetts and other cars almost as small and weighing hundreds of pounds less then the Sonic.

To summarize: I found the Sonic ride to be quiet, smooth, predictable, and most important from my point of view, fun.

Laborsmith

 

[warbirdfan]

I live in the foot hills of Virginia and have a long commute to work via I-66. When the wind really gets to whipping, it does become an interesting ride in my new Sonic sedan. Add a semi or two and things get dicey. Throw in some torrential rains and you've got some REAL excitement!

 

[laborsmith]

It may be I am more used to driving smaller cars. The Camaros I have owned in the past are the biggest cars I have owned since the 70's. I find the Sonic more stable on the highway then the J-Body cars I owned and almost if not as stable as the 2005 Cobalt SS/SC with the Quaife limited slip differential that I traded in for the 2010 1LT Camaro I no longer own.

Laborsmith

 

[Danny5]

I noticed my Sonic feels quite darty on the freeway, especially if there is any wind, nature or man made. This could be a function of tires. In the past, upgrading tires always made my cars drive, track, and ride better.

 

[jlslatton]

I drove a Jetta for 10 years and noticed the same effects with it. Small cars are just going to be tossed a bit behind a semi or in strong wind. Nothing that can't be controlled, however.

 

[Sonic]

I came in here to post "Thanks captain obvious" to the guy that wrote that article. What did he think would happen when driving behind a semi in a small car???

 

[RichieRocket]

I came in here to post "Thanks captain obvious" to the guy that wrote that article. What did he think would happen when driving behind a semi in a small car???

I agree Sonic, someone needs to tell this guy "No Duh!". The vortex shedding off a truck, van, SUV is going to push around a small car, buffeting it from side to side. I feel it in my civic. I have felt it driving a Windstar minivan, that is not a small vechicle, but it has lots of side surface area to get pushed around.

If this guy wants to tailgate big rigs, stiffen the tire sidewall flex by getting larger dia wheels and install beefier sway bars and poly bushings...

Maybe I'm misunderstanding, but I sense an underlying tone that the Sonic has some kind of design defect or aerodynamic problem even though the guy admits he never drove a sub-compact before....please, give me a break!

 

[oldertech]

The '92 Honda Civic hatch that I just sold was virtually unaffected by any wind, vortex,etc. Hoping I will not have issues like this in my Sonic.

 

[RichieRocket]

The '92 Honda Civic hatch that I just sold was virtually unaffected by any wind, vortex,etc. Hoping I will not have issues like this in my Sonic.

Wow, you never felt cross-winds? My civic 4-dr sedan definitley does...
Was your '92 hatch the 2-door hatch?
1992 Honda Civic DX 2dr Hatchback 1.5L 4-cyl. 5-speed Manual Features and Specs
I looked up some specs on edmunds.com. Your civic hatch is 6.7" shorter than the sonic and the civic is of course shorter in length (2 door vs. 4-door)...So the sonic has much more surface area to push on...and that area is higher up.

 

[BoG233]

I can say this I had my Sonic up to 130 mph it felt a little light ( a soft drift in the wheel bot not all that bad ) as far as win and the car its a little heavier than other subcompacts so I didn't feel tossed around at all . I don't tail gate or draft on the road just the track so I did not feel and thing coming off the trucks even when passing them .

 

[oldertech]

Wow, you never felt cross-winds? My civic 4-dr sedan definitley does...
Was your '92 hatch the 2-door hatch?
1992 Honda Civic DX 2dr Hatchback 1.5L 4-cyl. 5-speed Manual Features and Specs
I looked up some specs on edmunds.com. Your civic hatch is 6.7" shorter than the sonic and the civic is of course shorter in length (2 door vs. 4-door)...So the sonic has much more surface area to push on...and that area is higher up.

That was my car, the 2-door hatch. I had the VX model, that had extra wind mods from factory, extra air dam below the engine, and stuff like that. I had KYB GR2 shocks that were pretty stiff and it made for a great ride. This was the model that had an EPA of 56mpg highway when it was new (on the old grading scale.)

I'm expecting some more movement from wind, but hope it will be somewhat as good as the Cobalt I had. I really enjoyed that car on the highway. I'm looking forward to a quieter car than the Honda was, as it had virtually no sound deadening.

 

[RichieRocket]

That was my car, the 2-door hatch. I had the VX model, that had extra wind mods from factory, extra air dam below the engine, and stuff like that. I had KYB GR2 shocks that were pretty stiff and it made for a great ride. This was the model that had an EPA of 56mpg highway when it was new (on the old grading scale.)

I'm expecting some more movement from wind, but hope it will be somewhat as good as the Cobalt I had. I really enjoyed that car on the highway. I'm looking forward to a quieter car than the Honda was, as it had virtually no sound deadening.

Yeah, those civic hatchs had incredible mileage! Too bad they can't build them like that anymore. The lean-burn cruise gets great mpg but the hotter, lean, combustion produces too much NOx (nitrous oxides) to meet emission standards...

 

[AxelRipper]

Yeah, those civic hatchs had incredible mileage! Too bad they can't build them like that anymore. The lean-burn cruise gets great mpg but the hotter, lean, combustion produces too much NOx (nitrous oxides) to meet emission standards...

Not to mention the crashworthiness aspect of those tin cans.

 

[RichieRocket]

Not to mention the crashworthiness aspect of those tin cans.

Good point, 2100 lbs with no airbags or crumple zones. That would really suck gettig run over by someone talking on the phone in an Escalade

 

[RockTheShazbot]

I can say this I had my Sonic up to 130 mph it felt a little light ( a soft drift in the wheel bot not all that bad ) as far as win and the car its a little heavier than other subcompacts so I didn't feel tossed around at all . I don't tail gate or draft on the road just the track so I did not feel and thing coming off the trucks even when passing them .

Just curious did the rev limiter kick in it at point or did you just not wanna take it further than that? I'd be impressed if the top speed is higher than my celica gts which was 150 mph

 

[Gimpster]

Having just taken my car cross country, I think this guys is over stating it. Compared to my wifes Yaris this car is planted on the highway.

 

[Gimpster]

1994-95 Honda Civic's had front driver/passenger airbags 92-93 only had drivers as I recall.

A small point I know, but I owned a LOT of 92-95 Civics. Wrecked one pretty bad and I'm still here to talk about it.

Good point, 2100 lbs with no airbags or crumple zones. That would really suck gettig run over by someone talking on the phone in an Escalade